Add a root plugin.json manifest per the Agent Plugins specification
(https://agent-plugins.org); the skills/ layout already conformed, so
no skill moves were needed. Compatible clients now discover all six
skills automatically.
Aligns all wrapper versions at 1.1.0 (Cursor and Codex manifests had
drifted to 1.0.0), adds per-skill ChatGPT desktop display metadata, and
updates the release workflow to bump every manifest.
Antoine van der Lee